July 19, 2018
How Noise Harms Our Health

How Noise Harms Our Health

by Berkeley Wellness  

Cars honking, trains screeching, sirens blaring, music blasting—we live in a noisy world. Besides frayed nerves, noise exposure can cause irreversible hearing loss. Here’s what you need to know to protect yourself.

How does noise affect hearing?

Loud sounds can permanently damage the tiny hair cells in the inner ear (cochlea) that send sound information to the brain. The damage can occur from a brief exposure to a high-intensity sound—such as a gunshot—or from chronic or frequent exposure to moderately intense sounds. Of the estimated 48 millionAmericans who have some degree of hearing loss, about one-third can attribute it, at least in part, to noise.

Is everyone equally affected by noise?

Sensitivity varies. Due to genetics, some people can withstand longer exposure to high-intensity sound before it causes hearing loss. Other factors may also increase the risk of noise-induced hearing loss—smoking, diabetes, and hypertension, for example. Men are at higher risk than women, possibly because they tend to be exposed to more noise. And not all noise is equal in its effects: Besides how loud the sound is, its frequency (high pitch is more harmful), whether it is intermittent or continuous, and how far you are from the source all matter.

How is sound measured, and what is a dangerous level?

Loudness of sound is measured in decibels, which range from 0 (the faintest sound a human can hear) to 180 (the sound of a rocket launch) or more. Each 10-decibel increase represents a doubling of the perceived loudness. Prolonged exposure to levels over 85 (such as many lawn mowers, motorcycles, hair dryers, and power tools) is risky—and the higher the level, the less time it takes to cause damage. In fact, for every 3-decibel increase above 85, the amount of time you can safely be exposed to it is cut in half. A level above 120 (such as an ambulance siren, gun firing, or fireworks at close range) is painful and can cause immediate damage. Sounds below 75, however, are unlikely to harm your hearing even after long exposure.

Can your ears “get used to” noise?

No. You may habituate psychologically to noise so it becomes less noticeable or less annoying, but the ear does not build up tolerance. The effects are cumulative. Each noise exposure, if long or loud enough, adds to the damage.

What are the symptoms of noise-induced hearing loss?

They usually begin subtly, with hearing loss initially in the higher frequencies. Sounds may appear distorted or muffled, and people may sound like they are mumbling, especially when there is background noise. Ringing in the ears (tinnitus) may accompany noise-induced hearing loss. But because hearing loss is insidious, you may not realize you have it until other people notice it and tell you.

How harmful is listening to a personal music player?

Potentially very harmful. Many people are unaware of how high they turn up the volume, especially in noisy surroundings. If people around you can hear the music, or if you can’t hear people talking to you, the volume is too high. And if you experience tinnitus or muffled or distorted hearing afterwards, the music was definitely too loud. It’s possible to set a volume limit on some devices.

Are some headphones better than others?

If you use headphones in a noisy place, you’re better off with a pair that blocks out outside sounds as much as possible. Earphones that fit in the ear (like earplugs) are better at blocking background noises than are those that sit on top of the ear canal opening—as are any type of active noise-canceling headphones—so you are more likely to keep the music at a lower, safer level. “Bone-conducting” earphones, which create vibrations that travel through the skull to the inner ear, are touted as safer since they bypass the eardrum. This is not proven, however, and such devices often have poorer sound quality.

Does noise-induced hearing loss ever improve?

It can. The muffled hearing and ringing in the ears that you may experience after a concert, for instance, usually go away within a day or two. Hearing loss from a single high-intensity sound often improves, though it can take several months, and your hearing may not fully recover. But if you’re exposed to loud noise regularly, you’re more likely to experience permanent hearing loss.

Should I have my hearing tested?

Yes, if you are exposed to loud sounds on a regular basis, or if you notice a change in your hearing or develop tinnitus. To find an audiologist in your area, go to the website of the American Academy of Audiology.

Does noise affect health in other ways?

Loud or persistent noise affects quality of life, both mentally and physically. It can disturb sleep, impair work performance, increase the risk of cognitive problems, and cause anxiety, irritability, depression, and headaches in some people. Studies have linked noise exposure to increased blood pressure and heart rate and even heart abnormalities.

How can I reduce my noise exposure?

Turn down the volume of music players, move away from the source if possible, buy the quietest vacuum and other appliances that you can find, and use hearing protection (foam earplugs, protective earmuffs, or both) when engaging in noisy activities, such as mowing the lawn, or if you work in a loud environment. (The government sets standards for occupational noise exposure and requires that workers receive hearing protection devices if levels are high.) Simply putting your hands over your ears when a fire engine passes can block some noise, too. Also for your hearing’s sake—and that of your neighbors—don’t use leaf blowers, keep your car’s muffler and exhaust system in good shape, and use your horn only for emergencies. In addition, don’t install a car alarm; it won’t do much to prevent car theft anyway.

Also see: Misophonia: When Common Sounds Irritate You.